Gas-heated hot water heater

ABSTRACT

A shutter valve is located in the gas supply conduit of the gas burner of a water heating apparatus having several taps from which domestic water may be drawn. A venturi in the line leading to one of the taps produces a pressure differential in response to flow through that line. A diaphragm-type actuator is connected to the venturi and to the shutter valve to reduce the gas flow to the burner when that pressure differential occurs.

United States Patent Inventor App]. No.

Filed Patented Assignee Priority Hans Meier Remscheid, Germany 17,500

Mar. 9, 1970 Dec. 7, 1971 Job. Vaillant KG Remscheid, Germany Mar. 21,1969 Germany GAS-HEATED HOT WATER HEATER 9 Claims, 4 Drawing Figs.

US. Cl.

Int. Cl Field of Search faw-rm-H -ru-Hluh 56] References Cited UNITEDSTATES PATENTS 2,034,123 3/1936 Treiber 236/25 2,901,175 8/1959 Keppel236/25 3,184,164 5/1965 McCormick 236/34 3,414,050 12/1968 Anand 165/323,490,693 1/1970 Meier 237/8 D Primary Emminer- Edward .1. MichaelAttorney-Barbe, Robertson and Vandenburgh ABSTRACT: A shutter valve islocated in the gas supply cow duit of the gas burner of a water heatingapparatus having several taps from which domestic water may be drawn. Aventuri in the line leading to one of the taps produces a pressuredifferential in response to flow through that line. A diaphragm-typeactuator is connected to the venturi and to the shutter valve to reducethe gas flow to the burner when that pressure differential occurs.

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HAIZ? MEIER PM 52% & wwlflty BACKGROUND OF THE INVENTION 1. Prior ArtThe prior art includes a gas-heated hot water heater comprising acirculating water heater with a heat exchanger for heating domesticwater by the circulating water. Therein, the heat exchange is disposedin a connection line short-circuiting the heating circuit with provisionfor priority being given to the heating of the domestic water by thecirculating heating water when domestic water is drawn. In thisconnection, it is prior art to provide an automatic control device forproviding full gas supply during the heating-up period and, in someinstances, also when domestic water is drawn with a throttled gas supplyduring heating operation. This attained by providing a water actuatorresponding to a dynamic difi'erential pressure in the short-circuitingportion of the heating circuit, which throttles the gas supply when theconnection line is shut ofi or throttled. Thus, the changeover of thehot water heater to throttled performance is made dependent on the waterflow through the heating circuit containing the radiators. This waterflow is derived in the conventional manner, for instance, by means of aventuri tube or an apertured restrictor as dynamic differential pressureor by the flow resistance of the radiators between supply and returnflow conduits. In this prior arrangement, the restrictor is provided bya pair of stops rotatable with respect to each other and having cutoutportions, the diaphragm-type actuator engaging one of the stops in arotating sense against the action of a spring.

In such apparatus, domestic water heating would always be effected withfull performance of the appliance. Frequently, this is not desirable.Full performance of the apparatus is, for instance, required if largeamounts of hot water such as for filling a bathtub or for shower bathingshall be tapped. A smaller output is required at other locations where,for instance, water is tapped for filling the relatively smalllavatories. For this purpose, the full performance of the apparatus istoo great. In apparatus of the aforesaid type this will lead, forinstance, to an undesirably strong heating of the circulating water and,hence, of the tapped domestic water. This becomes noticeable in aparticularly disagreeable manner in circulating water heaters of greatoutput.

2. Present invention The present invention relates to a gas waterheating ap paratus having several taps in which the gas supply to theburner is controlled as a function of the flow through at least one ofthe taps.

It is an object of this invention to avoid the aforesaid disadvantagesof the prior apparatus.

According to the invention, in a gas-heated hot water heating apparatushaving several taps this is attained by having a restrictor incorporatedin the gas supply conduit to the burner, which is adjustable to areduced gas flow cross section by a flow sensor connected between hotwater heater and one of the taps. Thus, the gas supply to the burner isthrottled automatically in dependence on a flow sensor and operation iseffected with reduced heating output when water is drawn at a specifictap which belongs, for instance, to a lavatory.

In one embodiment, the passageway for flow of the domestic water isalready branched internally of the apparatus to form two conduitbranches from the water heater and the flow sensor is arranged in one ofthese conduit branches.

The arrangement may be such that the flow sensor is formed by a venturitube and a diaphragm-type actuator, that the gas restrictor is a pair ofstops rotatable with respect to each other and having cutout portions,and that the diaphragmdype actuator engages one of the stops in arotating sense against the action of a spring.

In another embodiment, the hot water heater is designed as a circulatingwater heater including a heat exchanger for heating domestic water bythe circulating water, with the heat exchanger being disposed in aconnection line short-circuiting the heating circuit, when domesticwater is tapped. A venturi tube is arranged in the heating circuitadapted to be short-circuited, by which a second diaphragm-type actuatoris operable, and that the rotatable stop is also operable by the seconddiaphragm-type actuator. Thus, a single stop is provided which throttlesthe gas supply both during heating operation only and also when tappingwater at specific taps. Throttling of the gas supply may be effected todiffering performance values of the different modes of operation.

DESCRIPTION OF DRAWINGS FIG. 1 schematically illustrates a circulatingwater heater embodying the invention, and including a heating system;

FIG. 2 illustrates the restrictor for throttling the gas supply;

FIG. 3 illustrates a modified embodied form of the invention; and

FIG. 4 illustrates another modification of the invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS The following disclosure is offeredfor public dissemination in return for the grant of a patent. Althoughit is detailed to ensure adequacy and aid understanding, this is notintended to prejudice that purpose of a patent which is to cover eachnew inventive concept therein no matter how others may later disguise itby variations in form or additions or further improvements. The claimsat the end hereof are intended as the chief aid toward this purpose, asit is these that meet the requirement of pointing out the parts,improvements, or combinations in which the inventive concepts are found.

In FIG. 1 a gas burner 1 is illustrated schematically. It is suppliedwith gas from a conduit 2 through a gas valve 3. As is conventional, thegas burner l is positioned below a heating section (not shown) closed atthe top by a multiple fin block 4 acting as a heat exchanger. Connectedto the input and output sides of a multiple fin block 4 are return flowconduit 5 and a supply flow conduit 6, respectively, of a circulationheating system. A circulating pump 7 is connected in the return flowconduit 5. The supply flow conduit 6 leads to a changeover valve 8 whichhas a connection 9' leading to bypass line 9. From the changeover valve8 a branch 6' of the supply flow conduit leads to the room radiators II,to which the return flow conduit 5 also is connected.

The bypass 9 directly communicates the supply flow conduit 6 with thereturn flow conduit 5 through a heat exchanger 10. Heat exchanger 10 hasa coil 10' through which domestic water flows. In the illustratedsetting of the changeover valve 8 the supply flow conduit 6 communicateswith the connection line 9 so that the circulating pump 7 generates awater circulation in a small circulation circuit through the multiplefin block 41, the supply flow conduit 6, the changeover valve 8, theconnection line 9 and return 5. At the same time, the heating circuitcontaining the radiators 11 and the branch 6' of the supply flow conduitis short-circuited.

The changeover valve 8 includes a valve closure 8 which is moved axiallyby a servomotor l2. Closure 8 also is designed as thermostatic expansionbody. A changeover valve 8 of the type indicated is more fully describedin the German Pat. ap-

plication No. V 29,774 X/36e, DBP l,266,944. As long as domestic wateris drawn through coil 10', the changeover valve 8 remains in theillustrated position. As soon as the draw of domestic water isinterrupted, the valve closing body 3' is shifted towards the right bythe servomotor 12, but it does not shut off the opening 9' of theconnection line 9 until the supply water in the supply flow conduit 6has exceeded a specific temperature.

Thus, during the initial heating-up period, the changeover valve 8assumes such a position that the communication of the supply flowconduit 6 is open to both conduit branch 6' and the connection line 9.Therefore, with relatively cold supply water, a large amount of waterflows through the connection line 9 due to the smaller flow resistanceand only a small amount of water flows to the radiators 11 through theconduit branch 6. As the temperature of the supply flow water increasesthe body 8 expands and the greater becomes the proportion of the waterflowing through the conduit branch 6 and the smaller becomes theproportion of the water flowing through the connection line 9.Ultimately, the connection line 9 is shut off altogether and the totalamount of water then flows into the heating circuit through 6.

The gas valve closure 3 is urged by a spring 13 to the seated positionon a valve-seat ring 14. The closure 3 is raised from the valve-seatring 14 by an electromagnet 16 provided with a dash pot device 15. Theelectromagnet 16 is energized through contacts 17 which are closed by adiaphragm-type water actuator 18. The diaphragm-type water actuator 18connects to a venturi tube 19 arranged in the supply flow conduit 6. Aslong as the circulating pump 7 is operating to produce water circulationin the system, a differential water pressure is generated at the venturitube 19, causing the water actuator 18 to respond and the magnet 16 tobe actuated. By this arrangement, acting as a water deficiency safetydevice, the gas valve 3 is held open water deficiency safety device, thegas valve 3 is held open while the circulating pump 7 is operatmg.

A gas restrictor is connected in front of the gas valve 3 (HO. 2) tothrottle the gas flow. in the disclosed embodiment, this gas restrictortakes the form of a shutter valve comprising a rotatable stop 20,rotatably mounted on a collar 21 of the valve seat ring 14. The stop 20has four solid sectors between which are openings. Sectors 20' covercorresponding sectorshaped apertures 14 of the valve-seat ring 14 to agreater or lesser extent depending upon the rotational position of stop20. A downwardly projecting radial lug 22 is provided on the rotatablestop 20 and is engaged by a driving pin 23. The driving pin 23 is urgedoutwardly by an encircling spring 230 toward the position at which theshutter valve is fully open. Against that urging the shutter valve isrotated toward the closed position by a water actuator 25, moving lever24 and pin 23.

The water actuator 25 has two connections x and y leading to twoconnections x and y respectively on venturi 30 and line 28. The coil inthe heat exchanger 10 communicates with the house water supply 26. Thedomestic water heated in the coil 10' is passed on through the hot waterconduit 27. The conduit 27 is divided into the branch conduits 28 and29. When the tap provided at the end of the branch conduit 29 is opened,there is no effect on actuator 25 and the position of stop so that theshutter valve remains fully open. However, when hot domestic water isdrawn through the branch conduit 28, a pressure differential is createdbetween pipes x and y at venturi 30. This pressure differential (actingthrough connections at and y) causes water actuator to rotate stop 20 toreduce the gas flow to burner 1 to a predetermined extent. The maximumwater flow through branch 28 is less than that though branch 29 due tothe presence of venturi 30 in branch 28. The extent to which the gasflow is reduced is correlated with this difference in maximum waterflow.

According to FIG. 3, the invention may also be used in a normalgas-heated instantaneous water heater which is not designed as acirculating water heater and whose water actuator 31 has a volumetricwater regulator 32. The hot water output of this apparatus isdistributed into two branch conduits 34 and 35 connected to the outputline 33. Though both branches the same, relatively small, amount ofwater can be drawn. While the amount of water which can be tapped fromthe first branch 34 is heated by the full gas load, when hot water isdrawn from the second branch 35, there is a pressure differential atconnections x and y of the flow sensor. In response to this pressuredifferential, actuator 25 partially closes the shutter valve 14, 20 toreduce the gas flow to the burner. This flow sensor includes a venturitube 36 arranged in branch conduit 35. The difierential pressure wateractuator 25 and shutter valve are similar to the embodiment of FIGS. 1and 2.

For drawing large amounts of water, such as when filling a tub, coldwater is admixed to the water heated with the full load (branch 34) to arelatively high temperature. The same, relatively small, amount of waterhaving a lower temperature and heated with partial load is, forinstance, suited for filling a lavatory from branch 35.

As illustrated in FIG. 4, changeover to partial load can also beefi'ected through a throttle valve 36 in the bypass channel 37, 38 ofthe volumetric gas governor designed in the conventional manner.

I claim:

1. In a gas water heater apparatus having a water line leading to aplurality of taps and including a gas burner with a gas conduit leadingto the burner, the improvement comprising:

a water flow sensor in one water line leading to one of the taps;

an adjustable gas flow restrictor in said conduit; and

control means connected to said sensor and to said restrictor forreducing the as flow in the conduit in response to the flow of water insaid one line.

2. in an apparatus as set forth in claim 1, wherein said sensor includesventuri;

said restrictor is a shutter valve including a rotatable stop;

and

said control means includes a diaphragm-type differential pressureactuator operatively connected to said stop and connected to theventuri.

3. In an apparatus as set forth in claim 2 including spring meansoperatively associated with said rotatable stop for urging said stop inone direction, said actuator being connected to move the stop in theother direction against said urging.

4. in an apparatus as set forth in claim 3 which apparatus is acirculating water heater with feed and return lines and a heat exchangerdevice for heating domestic water with a portion of the device connectedas a bypass between said feed and return lines, wherein said flow sensorbeing operatively connected to said heat exchanger device to respond toflow through said device only.

5. in an apparatus as set forth in claim 4, wherein said heat exchangerhas a domestic water conduit, said taps being downstream of saiddomestic water conduit.

6. In an apparatus as set forth in claim 1 which apparatus is acirculating water heater with feed and return lines and a heat exchangerdevice for heating domestic water with a portion of the device connectedas a bypass between said feed and return lines, wherein said flow sensorbeing operatively connected to said heat exchanger device to respond toflow through said device only.

7. In an apparatus as set forth in claim 6, wherein said heat exchangerhas a domestic water conduit, said taps being downstream of saiddomestic water conduit.

8. In an apparatus as set forth in claim 3 and having a finned blockheat exchanger heated directly by the burner heat, said heat exchangerhaving a conduit through which the domestic water flows, said line beingconnected to said conduit downstream thereof.

9. in an apparatus as set forth in claim 1 and having a finned blockheat exchanger heated directly by the burner heat, said heat exchangerhaving a conduit through which the domestic water flows, said line beingconnected to said conduit downstream thereof.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 625,4-23 Dated December 7. J 9'71 Invent Hans lieier It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Col. 1, line 8 "exchange" should be exchanger Col. 1,

line 16 after "This" insert is Col. 2, line 58 after "as" insert a Col.3, lines 19-20 after "open" delete water deficiency safety device, thegas valve 3 is held open Col. 3, line 52 "though" should be through Col.3, line 60 "Though" should be Through Col. 4, (Cl.l) line 22 "as" shouldbe gas Col. 4, line 25 (Cl. 2)

after "includes" insert a Signed and sealed this 20th day of June 1972.

(SEAL) Attest EDWARD M.FLETCHER, JR. ROBERT GOTTSGHALK Commissioner ofPatents Attesting Officer DRM PO-105O (10-69) uscoMM-Dc 80376-F'59 Q U SGOVERNMENY PRINYXNG OFFCE '96! D366 334

1. In a gas water heater apparatus having a water line leading to aplurality of taps and including a gas burner with a gas conduit leadingto the burner, the improvement comprising: a water flow sensor in onewater line leading to one of the taps; an adjustable gas flow restrictorin said conduit; and control means connected to said sensor and to saidrestrictor for reducing the gas flow in the conduit in response to theflow of water in said one line.
 2. In an apparatus as set forth in claim1, wherein said sensor includes a venturi; said restrictor is a shuttervalve including a rotatable stop; and said control means includes adiaphragm-type differential pressure actuator operatively connected tosaid stop and connected to the venturi.
 3. In an apparatus as set forthin claim 2 including spring means operatively associated with saidrotatable stop for urging said stop in one direction, said actuatorbeing connected to move the stop in the other direction against saidurging.
 4. In an apparatus as set forth in claim 3 which apparatus is acirculating water heater with feed and return lines and a heat exchangerdevice for heating domestic water with a portion of the device connectedas a bypass between said feed and return lines, wherein said flow sensorbeing operatively connected to said heat exchanger device to respond toflow through said device only.
 5. In an apparatus as set forth in claim4, wherein said heat exchanger has a domestic water conduit, said tapsbeing downstream of said domestic water conduit.
 6. In an apparatus asset forth in claim 1 which apparatus is a circulating water heater withfeed and return lines and a heat exchanger device for heating domesticwater with a portion of the device connected as a bypass between saidfeed and return lines, wherein said flow sensor being operativelyconnected to said heat exchanger device to respond to flow through saiddevice only.
 7. In an apparatus as set forth in claim 6, wherein saidHeat exchanger has a domestic water conduit, said taps being downstreamof said domestic water conduit.
 8. In an apparatus as set forth in claim3 and having a finned block heat exchanger heated directly by the burnerheat, said heat exchanger having a conduit through which the domesticwater flows, said line being connected to said conduit downstreamthereof.
 9. In an apparatus as set forth in claim 1 and having a finnedblock heat exchanger heated directly by the burner heat, said heatexchanger having a conduit through which the domestic water flows, saidline being connected to said conduit downstream thereof.